Adjustable linkage



2 Sheets-Sheet 1 Filed June 19, 195:5

INVENTOR. WI//IOI77 6. E dmuno'son' His Afforney Patented June 10, 1958 ADJUSTABLE LINKAGE William C. Edmundson, Anderson, Ind., assignor to General Motors Corporation, Detroit,'Mich., a corporation of Delaware Application June 19, 1953, Serial No. 362,883

3 Claims. (Cl. 74-586) This invention relates to new and useful improvements in link connections and more particularlyof the adjustable type.

An object of the present invention isto provide an adjustable linkage between two movable-parts such that the two movable parts may be connected one with respect to the other irrespective of variable distance between the two movable parts or so that the linkage length between the two movable parts may be changed for thepurpose of adjustment of linkage length to a critical value.

Another object of the present invention is to provide a linkage that is adjustable a definite amount within reasonable limits to increase or decrease the distance of linkage length between a pair of movable parts.

Another object of the present invention is to provide an adjustable linkage between a pair of movable members which linkage is proof against hinging or collapse between the elements to which the linkage is connected.

Another object of the invention istoprovide an adjustable linkage between two movable parts so that the length of the linkage can be adjusted as to length without introducing a tendency to buckle or bend.

Further objects and advantages of the present invention will be apparent from the followingdescription'reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is'clearly shown.

In the drawing:

Fig. l is a side elevation of an engine starting mechanism embodying the present invention.

Fig. 2 is an enlarged sectional view of the linkage embodying the present invention and taken on-line 22 of Fig. 1.

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2.

Fig. 4 is an exploded perspective view of the adjustable linkage elements embodying the present invention.

Fig. 5 is a sectional view of a modified form of a clevis shown in Fig. 2.

Fig. 6 is a sectional view of a split clevis capable of being used with the clevis shown in Fig. 5.

Fig. 7 is a top plan view of a clevis shown in Fig. 2.

Fig. 8 is a plan view of a one-piece clevis which is capable of being used with the clevis shown in Fig. 7.

Fig. 9 is an end view of clevis shown in Fig. 8 and looking in the direction of arrow 9 in Fig. 11.

Fig. 10 is a sectional view of the clevises shown in Figs. 7 and 8 in assembled relation.

Fig. 11 is a side view of the clevis shown in Fig. 8 and looking in the direction of arrow 11 ofFig. 8.

Referring to Fig. 1, the invention is illustrated as embodied in a mechanism in which a pinion 20. is mounted to slide upon a splined power. shaft 21. The shaft 21 may be rotated by power derived from an electric motor 22, and the shaft is journalled, at one-end in a housing 23 which is provided with a flange 24 by which it'may be attached to a flywheel housing, not shown, of an engine in the usual manner. The other end of the shaft is journalled'in a bearing provided by an end frame 25 attached toa field frame 26 of the electric motor.

The shaft'has splines engaging splines of a sleeve 27 connected with a driving member of a one-way or overrunning clutch 28. Acollar 29 is slidable on the sleeve 27 and is retained by a split wire spring, not shown.. A spring 31 is retained under initial compression between the collar 29 and the clutch 28. For further details of the starter drive reference is made to Dyer Patent 2,302,687.

The'housing 23. supports a pivot screw 35 for a hub of a lever 36 made of two parts and held together. at the upper end in. any suitable manner, for example, spot welding or.rivets. The lower end of the lever 36 is bifurcated to provide two arms 38, each carrying a stud 39 received between flanges of the collar 29. A spring 40 is coiled around the lever hub and has one end 41 pressing against the frame 24 and the other end 42 on the lever to urge the lever 36 in a clockwise direction as viewed. in Fig. 1. counterclockwise movement of the lever 36. elfects movement of the pinion 20 toward the engine flywheel gear, not shown. The lever 36 has a slot 45 for receiving a pin 46 extending across arms of an adjustable link 50. The slot 45 in lever 36 provides a lost motion connection which permits the opening of starter switch S in the manner described in Dyer Patent 2,302,687.

The adjustable link 50 in the present instance cornprises a clevis or U-shaped member 51 having a yoke 52 and spaced parallel arms 53 and 54. The arms extend through slots 55 in a plate 56 which retains the yoke 52. The plate 56 is attached to an armature 57 of a solenoid unit or electromagnet 66. The solenoid unit 60 includes an outer shell 61 to which is spot welded a bracket 62 which has flanges 63 curved to fit motor field frame 26 and these flanges provide slots 64 for receiving screws 65 for attaching the bracket to the field frame 26. For further details of the solenoid unit, reference is made to Antonidis Patent 2,482,534.

A feature of the present invention comprises the adjustable link 50 including the clevis 51 having the arm 53 provided with a tapped flanged opening 66 while the arm 54 has a plain opening 67 in mutual alignment with the tapped opening 66. The inner surface of the arm 54 is formed with locking means, for example, a plurality of corrugations or transverse spaced ribs 69 to provide alternate ribs and grooves. The link 50 also includesra clevis 70 made of two plates 71 and 72 held together by a weld 19. The clevis is operatively connected with the clevis 51 in the manner shown in Fig. 3 and when in stacked relation as shown the plates 71 and 72 fill the spacing between the arms 53 and 54 of clevis 51. The plate 71 has a pair of parallel flanges 73 rigidly connected at one end to the plate 71 which straddle the free end of the arm 53. The plate 71 has an elongated slot 74 which registers with the tapped opening 66. The plate 72 is provided with a pair of spaced flanges 75 rigidly connected at one end to the plate 72 and has an elongated slot 76 which registers with the opening 67. The outer face of the plate 72 is-provided with locking means or transverse ribs 77 which cooperate with the corresponding locking means 69 of arm 54. The plates 71 and 72 are offset at 89 so that free ends of the plates will be in alignment with the arms 53 and 54. The free ends of the plates 71-.and 72 are disposed on opposite sides of the lever 36 andhave openings 78 to receive a headed pin 46 which extends through the slot 45 in the lever 36. The pin may be held in assembled relation with'the plates 71, 72, by a cotter pin 80 as shown in Fig. 2.

The clevis'70 is adjustable and held in adjusted position within the confines of the arms 53 and 54 of the clevis 51,

by a screw 81. The screw 81 is received by the opening 67 and passes through the elongated slots and threaded into the tapped hole 66. .The transverse ribs 69 of the arm 54 and the ribs 77 of the plate 72 lock the plates in position against lineal movement when the screw is tightened. The flanges 73 of plate 71 prevent the plates from rotating about the screw 81;

In Figs. and 6 an optional form of an adjustable link 51a is shown whose principles of operation are substantially as those of the form shown in Fig. 1 through Fig. 4, but whose mechanical construction is slightly diflerent. In Fig. 5 the armature 57, and disc 56 have been omitted,

but it is to be understood that the clevis 51a is mounted to the armature 57 in a similar manner to that described for clevis 51. The clevis 51a comprises a pair of arms 53a and 54a and each arm is formed with corrugations or transverse ribs 69a. In Fig. 6, a split clevis is shown and comprises a plate 71a and a plate 72, The plate 71a is provided with corrugations or spaced n'bs 7111 which match with the corrugation or spaced ribs 69a on arm 53a. The ribs lock the plates 71a and 72 against lineal movement, when the plates are placed between the legs 53a and 54a and the screw 81 is tightened.

In Figs. 7 through 11' a preferred form of adjustable link parts are shown whose principle of operation is the same as those of the previous forms but a one-piece clevis 85 is used instead of a clevis made of two pieces. Fig. 8 shows the clevis 85 comprising a U-shaped member having a yoke 86 and spaced parallel arms 87 and 88 which are offset at 89 so that when the clevis 85 is assembled with the clevis 51 the arms extending from the offset 89 to the right, as shown in Fig. 8, will be in alignment with the arms 53 and 54. Each arm 87 and 88 has parallel flanges 90 which straddle respectively arms 53 and 54 of clevis 51. The arm 88 is formed with serrations or transverse ribs 92 between the flanges 90. The arms 87 and 88 have elongated slots or openings 93 which register with a tapped opening 66 in arm 53. A prong 94 is associated with the arm 87 and is arranged so as to engage the inner surface of the arm 88. The purpose of the prong 94 is to prevent the clevis 85 from collapsing and to maintain the arms 87 and 88 in their parallel spaced relation when the screw 81 is tightened.

Due to slight variations in the manufacture of parts for starting motors it is possible that the pinion will not fully mesh with the flywheel gear after the starting motor is attached to the flywheel gear housing. In order that the pinion can be fully meshed with the flywheel gear, not shown, it is necessary to provide the proper linkage between the armature 57 and lever 36 so that the pinion 20, shown in Fig. 1, is moved from the demeshed position to fully meshed position by the solenoid armature 57. The distance through which the armature 57 and hence the pinion 20 moves is determined by the length of the linkage 50 between the armature 57 and lever 36. To change thelength of the linkage 50, the screw 81 is loosened and the plates 71 and 72 of clevis, shown in Fig. 1 through Fig. 4, are moved relative to the clevis 51 to the required position, and the plates are secured in the desired position by tightening the screw 81. This adjustment does not change the position of the solenoid unit 60 on the frame or the established relation of lever 36 with respect to housing 23.

In the modified form of the invention shown in Figs. 5 and 6, both plates 71a and 72, which comprise the split clevis, must be moved due to the fact that the openings 78 must be in mutual alignment.

While the embodiment of the present invention as herein disclosed constitutes a preferred form it is to be understood other forms might be adopted.

What is claimed is as follows:

1. An adjustable linkage for transmitting motion between two movable members comprising in combina- 4 tion; a first clevis operatively connected with one of the members, said clevis including spaced arms and provided with mutually aligned openings adjacent the free ends of said arms, a second clevis having a yoke portion and spaced arms and having the free ends of said arms adapted to be operatively connected with the other member and adapted to have the yoke portion disposed between the arms of the first clevis, said arms of the second clevis having two pairs of parallel flanges and longitudinal slots between the flanges, screw means received by the openings in the free ends of the arms in the first clevis and passing through the slots of the arms of the second clevis for securing the clevises together, and means including interenga'ging serrated surface portions on at least one of the arms of each clevis for restraining relative movement between the two clevises when the screw means secures said clevises together and when said yoke portion of the second clevis is disposed between the arms of said first clevis.

2; An adjustable linkage for transmitting motion between two movable members comprising in combination; a first clevis adapted to be operatively connected by its mid portion with one of the members, said clevis including spaced arms and provided with mutually aligned openings adjacent the free ends thereof, a second clevis having a yoke portion thereof adapted to be spanned by the arms of the first clevis when the free ends of the arms of the second clevis are in alignment with the arms of the first clevis and the free ends thereof are operatively connected with the other member, said yoke portion of the second clevis having parallel pairs of flanges and elongated slots in the arm portions thereof, one of said pairs of flanges being adapted to embrace one of the arms of the first clevis to prevent relative rotation between the first and second clevises and the other of said flanges being adapted to maintain the arms of said second clevis -in spaced relation, screw means received by the openings in the free ends of the arms in the first clevis and passing through the slots of arms of the second clevis for securing the clevises together; and means including interengaging serrated surface portions between at least one of the adjacent arms of each clevis for restraining relative movement between the two clevises when the screw means is tightened.

3. An adjustable linkage for transmitting motion between two movable members, comprising in combination; a clevis operatively connected with one of the members, including a pair of spaced arms each having mutually aligned openings adjacent the free ends of said arms, a second pair of spaced arms having the free ends thereof adapted to be operatively connected with the other member, a pair of spaced flanges on one of the arms of said second pair of spaced arms arranged to embrace one of the arms of said clevis for holding said arms in axial alignment, flange means on the other of said second pair of arms for maintaining the second pair of arms spaced from each other, longitudinally extending slots in each of said second pair of arms, screw means received by the openings in the free ends of the arms in the first clevis and passing through the slots in the arms of said second pair of arms for securing said second pair of arms to the arms of said clevis, and means including a serrated surface on at least one of the arms of said clevis and on at between the arms of said clevis.

References Cited in the file of this patent UNITED STATES PATENTS Thompson Sept. 28, 1909 Crawford et al. Oct. 27, 1931 

